scholarly journals Light-Dependent Functions of the Fusarium fujikuroi CryD DASH Cryptochrome in Development and Secondary Metabolism

2013 ◽  
Vol 79 (8) ◽  
pp. 2777-2788 ◽  
Author(s):  
Marta Castrillo ◽  
Jorge García-Martínez ◽  
Javier Avalos
Keyword(s):  
Secondary Metabolism ◽  
Nitrogen Starvation ◽  
Phytopathogenic Fungus ◽  
Fusarium Fujikuroi ◽  
Mrna Levels ◽  
Wild Type ◽  
Gene Encoding ◽  
Content Type ◽  
Gibberellin Production ◽  
In The Wild

ABSTRACTDASH (Drosophila,Arabidopsis,Synechocystis, human) cryptochromes (cry-DASHs) constitute a subgroup of the photolyase cryptochrome family with diverse light-sensing roles, found in most taxonomical groups. The genome ofFusarium fujikuroi, a phytopathogenic fungus with a rich secondary metabolism, contains a gene encoding a putative cry-DASH, named CryD. The expression of thecryDgene is induced by light in the wild type, but not in mutants of the “white collar” genewcoA. Targeted ΔcryDmutants show light-dependent phenotypic alterations, including changes in morphology and pigmentation, which disappear upon reintroduction of a wild-typecryDallele. In addition to microconidia, the colonies of the ΔcryDmutants produced under illumination and nitrogen starvation large septated spores called macroconidia, absent in wild-type colonies. The ΔcryDmutants accumulated similar amounts of carotenoids to the control strain under constant illumination, but produced much larger amounts of bikaverin under nitrogen starvation, indicating a repressing role for CryD in this biosynthetic pathway. Additionally, a moderate photoinduction of gibberellin production was exhibited by the wild type but not by the ΔcryDmutants. The phenotypic alterations of the ΔcryDmutants were only noticeable in the light, as expected from the low expression ofcryDin the dark, but did not correlate with mRNA levels for structural genes of the bikaverin or gibberellin biosynthetic pathways, suggesting the participation of CryD in posttranscriptional regulatory mechanisms. This is the first report on the participation of a cry-DASH protein in the regulation of fungal secondary metabolism.

scholarly journals Regulation of Carotenogenesis and Secondary Metabolism by Nitrogen in Wild-Type Fusarium fujikuroi and Carotenoid-Overproducing Mutants

2008 ◽  
Vol 75 (2) ◽  
pp. 405-413 ◽  
Author(s):  
Roberto Rodríguez-Ortiz ◽  
M. Carmen Limón ◽  
Javier Avalos
Keyword(s):  
Nitrogen Availability ◽  
Polyketide Synthase ◽  
Nitrogen Starvation ◽  
Carotenoid Biosynthesis ◽  
Gibberella Fujikuroi ◽  
Fusarium Fujikuroi ◽  
Wild Type ◽  
Carotenoid Accumulation ◽  
Gibberellin Production ◽  
In The Wild

ABSTRACT The fungus Fusarium fujikuroi (Gibberella fujikuroi MP-C) produces metabolites of biotechnological interest, such as gibberellins, bikaverins, and carotenoids. Gibberellin and bikaverin productions are induced upon nitrogen exhaustion, while carotenoid accumulation is stimulated by light. We evaluated the effect of nitrogen availability on carotenogenesis in comparison with bikaverin and gibberellin production in the wild type and in carotenoid-overproducing mutants (carS). Nitrogen starvation increased carotenoid accumulation in all strains tested. In carS strains, gibberellin and bikaverin biosynthesis patterns differed from those of the wild type and paralleled the expression of key genes for both pathways, coding for geranylgeranyl pyrophosphate (GGPP) and kaurene synthases for the former and a polyketide synthase for the latter. These results suggest regulatory connections between carotenoid biosynthesis and nitrogen-controlled biosynthetic pathways in this fungus. Expression of gene ggs1, which encodes a second GGPP synthase, was also derepressed in the carS mutants, suggesting the participation of Ggs1 in carotenoid biosynthesis. The carS mutations did not affect genes for earlier steps of the terpenoid pathway, such as fppS or hmgR. Light induced carotenoid biosynthesis in the wild type and carRA and carB levels in the wild-type and carS strains irrespective of nitrogen availability.

scholarly journals Identification and Regulation offusA, the Polyketide Synthase Gene Responsible for Fusarin Production in Fusarium fujikuroi

2012 ◽  
Vol 78 (20) ◽  
pp. 7258-7266 ◽  
Author(s):  
Violeta Díaz-Sánchez ◽  
Javier Avalos ◽  
M. Carmen Limón
Keyword(s):  
Nitrogen Availability ◽  
Polyketide Synthase ◽  
High Sensitivity ◽  
Targeted Mutagenesis ◽  
Fusarium Fujikuroi ◽  
Mrna Levels ◽  
Wild Type ◽  
Sequence Comparisons ◽  
Content Type ◽  
Polyketide Synthase Gene

ABSTRACTFusarins are a class of mycotoxins of the polyketide family produced by differentFusariumspecies, including the gibberellin-producing fungusFusarium fujikuroi. Based on sequence comparisons between polyketide synthase (PKS) enzymes for fusarin production in otherFusariumstrains, we have identified theF. fujikuroiorthologue, calledfusA. The participation offusAin fusarin biosynthesis was demonstrated by targeted mutagenesis. Fusarin production is transiently stimulated by nitrogen availability in this fungus, a regulation paralleled by thefusAmRNA levels in the cell. Illumination of the cultures results in a reduction of the fusarin content, an effect partially explained by a high sensitivity of these compounds to light. Mutants of thefusAgene exhibit no external phenotypic alterations, including morphology and conidiation, except for a lack of the characteristic yellow and/or orange pigmentation of fusarins. Moreover, thefusAmutants are less efficient than the wild type at degrading cellophane on agar cultures, a trait associated with pathogenesis functions inFusarium oxysporum. ThefusAmutants, however, are not affected in their capacities to grow on plant tissues.

scholarly journals SpyA, a C3-Like ADP-Ribosyltransferase, Contributes to Virulence in a Mouse Subcutaneous Model of Streptococcus pyogenes Infection

2011 ◽  
Vol 79 (6) ◽  
pp. 2404-2411 ◽  
Author(s):  
Jessica S. Hoff ◽  
Mark DeWald ◽  
Steve L. Moseley ◽  
Carleen M. Collins ◽  
Jovanka M. Voyich
Keyword(s):  
Streptococcus Pyogenes ◽  
Lesion Size ◽  
Infected Tissue ◽  
Infection Model ◽  
Mrna Levels ◽  
Wild Type ◽  
Gene Encoding ◽  
Content Type ◽  
Mouse Infection Model ◽  
Adp Ribosyltransferase

ABSTRACTStreptococcus pyogenesis an important human pathogen with an expansive repertoire of verified and putative virulence factors. Here we demonstrate that a mutant deficient in the production of the streptococcal ADP-ribosyltransferase SpyA generates lesions of reduced size in a subcutaneous mouse infection model. At early stages of infection, when the difference in lesion size is first established, inflamed tissue isolated from lesions of mice infected withspyAmutant bacteria has higher levels of mRNA encoding the chemokines CXCL1 and CCL2 than does tissue isolated from mice infected with wild-type bacteria. In addition, at these early times, the mRNA levels for the gene encoding the intermediate filament vimentin are higher in the mutant-infected tissue. As wound resolution progresses, mRNA levels of the gene encoding matrix metallopeptidase 2 are lower in mutant-infected tissue. Furthermore, we demonstrate that thespyAmutant is internalized more efficiently than wild-type bacteria by HeLa cells. We conclude that SpyA contributes to streptococcal pathogenesis in the mouse subcutaneous infection model. Our observations suggest that the presence of SpyA delays wound healing in this model.

scholarly journals Two Histone Deacetylases, FfHda1 and FfHda2, Are Important for Fusarium fujikuroi Secondary Metabolism and Virulence

2013 ◽  
Vol 79 (24) ◽  
pp. 7719-7734 ◽  
Author(s):  
L. Studt ◽  
F. J. Schmidt ◽  
L. Jahn ◽  
C. M. K. Sieber ◽  
L. R. Connolly ◽  
...  
Keyword(s):  
Secondary Metabolism ◽  
Secondary Metabolite ◽  
Filamentous Fungi ◽  
Histone Deacetylases ◽  
Control Plant ◽  
Gene Clusters ◽  
Phytopathogenic Fungus ◽  
Fusarium Fujikuroi ◽  
Content Type ◽  
Encoding Genes

ABSTRACTHistone modifications are crucial for the regulation of secondary metabolism in various filamentous fungi. Here we studied the involvement of histone deacetylases (HDACs) in secondary metabolism in the phytopathogenic fungusFusarium fujikuroi, a known producer of several secondary metabolites, including phytohormones, pigments, and mycotoxins. Deletion of three Zn2+-dependent HDAC-encoding genes,ffhda1,ffhda2, andffhda4, indicated that FfHda1 and FfHda2 regulate secondary metabolism, whereas FfHda4 is involved in developmental processes but is dispensable for secondary-metabolite production inF. fujikuroi. Single deletions offfhda1andffhda2resulted not only in an increase or decrease but also in derepression of metabolite biosynthesis under normally repressing conditions. Moreover, double deletion of both theffhda1andffhda2genes showed additive but also distinct phenotypes with regard to secondary-metabolite biosynthesis, and both genes are required for gibberellic acid (GA)-induced bakanae disease on the preferred host plant rice, as Δffhda1Δffhda2mutants resemble the uninfected control plant. Microarray analysis with a Δffhda1mutant that has lost the major HDAC revealed differential expression of secondary-metabolite gene clusters, which was subsequently verified by a combination of chemical and biological approaches. These results indicate that HDACs are involved not only in gene silencing but also in the activation of some genes. Chromatin immunoprecipitation with the Δffhda1mutant revealed significant alterations in the acetylation state of secondary-metabolite gene clusters compared to the wild type, thereby providing insights into the regulatory mechanism at the chromatin level. Altogether, manipulation of HDAC-encoding genes constitutes a powerful tool to control secondary metabolism in filamentous fungi.

scholarly journals Expression and function of the cdgD gene, encoding a CHASE–PAS-DGC-EAL domain protein, in Azospirillum brasilense

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
José Francisco Cruz-Pérez ◽  
Roxana Lara-Oueilhe ◽  
Cynthia Marcos-Jiménez ◽  
Ricardo Cuatlayotl-Olarte ◽  
María Luisa Xiqui-Vázquez ◽  
...  
Keyword(s):  
Azospirillum Brasilense ◽  
Type Strain ◽  
Wild Type Strain ◽  
Soil Conditions ◽  
Wild Type ◽  
Gene Encoding ◽  
Wheat Roots ◽  
Genes Encoding ◽  
In The Wild ◽  
Plant Growth Promoting

AbstractThe plant growth-promoting bacterium Azospirillum brasilense contains several genes encoding proteins involved in the biosynthesis and degradation of the second messenger cyclic-di-GMP, which may control key bacterial functions, such as biofilm formation and motility. Here, we analysed the function and expression of the cdgD gene, encoding a multidomain protein that includes GGDEF-EAL domains and CHASE and PAS domains. An insertional cdgD gene mutant was constructed, and analysis of biofilm and extracellular polymeric substance production, as well as the motility phenotype indicated that cdgD encoded a functional diguanylate protein. These results were correlated with a reduced overall cellular concentration of cyclic-di-GMP in the mutant over 48 h compared with that observed in the wild-type strain, which was recovered in the complemented strain. In addition, cdgD gene expression was measured in cells growing under planktonic or biofilm conditions, and differential expression was observed when KNO3 or NH4Cl was added to the minimal medium as a nitrogen source. The transcriptional fusion of the cdgD promoter with the gene encoding the autofluorescent mCherry protein indicated that the cdgD gene was expressed both under abiotic conditions and in association with wheat roots. Reduced colonization of wheat roots was observed for the mutant compared with the wild-type strain grown in the same soil conditions. The Azospirillum-plant association begins with the motility of the bacterium towards the plant rhizosphere followed by the adsorption and adherence of these bacteria to plant roots. Therefore, it is important to study the genes that contribute to this initial interaction of the bacterium with its host plant.

scholarly journals Controlled Transcription of Regulator Gene carS by Tet-on or by a Strong Promoter Confirms Its Role as a Repressor of Carotenoid Biosynthesis in Fusarium fujikuroi

2020 ◽  
Vol 9 (1) ◽  
pp. 71
Author(s):  
Julia Marente ◽  
Javier Avalos ◽  
M. Carmen Limón
Keyword(s):  
Wild Strain ◽  
Ring Finger ◽  
Carotenoid Biosynthesis ◽  
Negative Regulator ◽  
Fusarium Fujikuroi ◽  
Structural Genes ◽  
Gene Encoding ◽  
In The Wild ◽  
Set Up

Carotenoid biosynthesis is a frequent trait in fungi. In the ascomycete Fusarium fujikuroi, the synthesis of the carboxylic xanthophyll neurosporaxanthin (NX) is stimulated by light. However, the mutants of the carS gene, encoding a protein of the RING finger family, accumulate large NX amounts regardless of illumination, indicating the role of CarS as a negative regulator. To confirm CarS function, we used the Tet-on system to control carS expression in this fungus. The system was first set up with a reporter mluc gene, which showed a positive correlation between the inducer doxycycline and luminescence. Once the system was improved, the carS gene was expressed using Tet-on in the wild strain and in a carS mutant. In both cases, increased carS transcription provoked a downregulation of the structural genes of the pathway and albino phenotypes even under light. Similarly, when the carS gene was constitutively overexpressed under the control of a gpdA promoter, total downregulation of the NX pathway was observed. The results confirmed the role of CarS as a repressor of carotenogenesis in F. fujikuroi and revealed that its expression must be regulated in the wild strain to allow appropriate NX biosynthesis in response to illumination.

Transmembrane prolyl 4-hydroxylase is a fourth prolyl 4-hydroxylase regulating EPO production and erythropoiesis

Blood ◽  
2012 ◽  
Vol 120 (16) ◽  
pp. 3336-3344 ◽  
Author(s):  
Anu Laitala ◽  
Ellinoora Aro ◽  
Gail Walkinshaw ◽  
Joni M. Mäki ◽  
Maarit Rossi ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Mrna Level ◽  
Hypoxia Inducible Factor ◽  
Mrna Levels ◽  
Wild Type ◽  
Α Subunit ◽  
Hepcidin Expression ◽  
In The Wild ◽  
Hepcidin Mrna

AbstractAn endoplasmic reticulum transmembrane prolyl 4-hydroxylase (P4H-TM) is able to hydroxylate the α subunit of the hypoxia-inducible factor (HIF) in vitro and in cultured cells, but nothing is known about its roles in mammalian erythropoiesis. We studied such roles here by administering a HIF-P4H inhibitor, FG-4497, to P4h-tm−/− mice. This caused larger increases in serum Epo concentration and kidney but not liver Hif-1α and Hif-2α protein and Epo mRNA levels than in wild-type mice, while the liver Hepcidin mRNA level was lower in the P4h-tm−/− mice than in the wild-type. Similar, but not identical, differences were also seen between FG-4497–treated Hif-p4h-2 hypomorphic (Hif-p4h-2gt/gt) and Hif-p4h-3−/− mice versus wild-type mice. FG-4497 administration increased hemoglobin and hematocrit values similarly in the P4h-tm−/− and wild-type mice, but caused higher increases in both values in the Hif-p4h-2gt/gt mice and in hematocrit value in the Hif-p4h-3−/− mice than in the wild-type. Hif-p4h-2gt/gt/P4h-tm−/− double gene-modified mice nevertheless had increased hemoglobin and hematocrit values without any FG-4497 administration, although no such abnormalities were seen in the Hif-p4h-2gt/gt or P4h-tm−/− mice. Our data thus indicate that P4H-TM plays a role in the regulation of EPO production, hepcidin expression, and erythropoiesis.

scholarly journals Genetic Differentiation Associated with Fumonisin and Gibberellin Production in JapaneseFusarium fujikuroi

2018 ◽  
Vol 85 (1) ◽  
Author(s):  
Haruhisa Suga ◽  
Mitsuhiro Arai ◽  
Emi Fukasawa ◽  
Keiichi Motohashi ◽  
Hiroyuki Nakagawa ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Genetic Relationships ◽  
Pathogenic Fungus ◽  
Phylogenetic Analyses ◽  
Aflp Markers ◽  
Fusarium Fujikuroi ◽  
Rice Seedlings ◽  
Bakanae Disease ◽  
Content Type ◽  
Gibberellin Production

ABSTRACTFusarium fujikuroiis a pathogenic fungus that infects rice. It produces several important mycotoxins, such as fumonisins. Fumonisin production has been detected in strains of maize, strawberry, and wheat, whereas it has not been detected in strains from rice seedlings infested with bakanae disease in Japan. We investigated the genetic relationships, pathogenicity, and resistance to a fungicide, thiophanate-methyl (TM), in 51 fumonisin-producing strains and 44 nonproducing strains. Phylogenetic analyses based on amplified fragment length polymorphism (AFLP) markers and two specific genes (a combined sequence of translation elongation factor 1α [TEF1α] and RNA polymerase II second-largest subunit [RPB2]) indicated differential clustering between the fumonisin-producing and -nonproducing strains. One of the AFLP markers, EATMCAY107, was specifically present in the fumonisin-producing strains. A specific single nucleotide polymorphism (SNP) between the fumonisin-producing and nonproducing strains was also detected inRPB2, in addition to an SNP previously found inTEF1α. Gibberellin production was higher in the nonproducing than in the producing strains according to anin vitroassay, and the nonproducing strains had the strongest pathogenicity with regard to rice seedlings. TM resistance was closely correlated with the cluster of fumonisin-nonproducing strains. The results indicate that intraspecific evolution in JapaneseF. fujikuroiis associated with fumonisin production and pathogenicity. Two subgroups of JapaneseF. fujikuroi, designated G group and F group, were distinguished based on phylogenetic differences and the high production of gibberellin and fumonisin, respectively.IMPORTANCEFusarium fujikuroiis a pathogenic fungus that causes rice bakanae disease. Historically, this pathogen has been known asFusarium moniliforme, along with many other species based on a broad species concept. Gibberellin, which is currently known as a plant hormone, is a virulence factor ofF. fujikuroi. Fumonisin is a carcinogenic mycotoxin posing a serious threat to food and feed safety. Although it has been confirmed thatF. fujikuroiproduces gibberellin and fumonisin, production varies among strains, and individual production has been obscured by the traditional appellation ofF. moniliforme, difficulties in species identification, and variation in the assays used to determine the production of these secondary metabolites. In this study, we discovered two phylogenetic subgroups associated with fumonisin and gibberellin production in JapaneseF. fujikuroi.

scholarly journals Activation of 2,4-Diaminoquinazoline in Mycobacterium tuberculosis by Rv3161c, a Putative Dioxygenase

2018 ◽  
Vol 63 (1) ◽  
Author(s):  
Eduard Melief ◽  
Shilah A. Bonnett ◽  
Edison S. Zuniga ◽  
Tanya Parish
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mutant Strain ◽  
Type Strain ◽  
Wild Type Strain ◽  
Type A ◽  
Wild Type ◽  
Metabolite Analysis ◽  
Content Type ◽  
Data Support ◽  
In The Wild

ABSTRACT The diaminoquinazoline series has good potency against Mycobacterium tuberculosis. Resistant isolates have mutations in Rv3161c, a putative dioxygenase. We carried out metabolite analysis on a wild-type strain and an Rv3161c mutant strain after exposure to a diaminoquinazoline. The parental compound was found in intracellular extracts from the mutant but not the wild type. A metabolite consistent with a monohydroxylated form was identified in the wild type. These data support the hypothesis that Rv3161c metabolizes diaminoquinazolines in M. tuberculosis.

scholarly journals Characterization and Analysis of Anthocyanin-Related Genes in Wild-Type Blueberry and the Pink-Fruited Mutant Cultivar ‘Pink Lemonade’: New Insights into Anthocyanin Biosynthesis

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1296
Author(s):  
Jose V. Die ◽  
Richard W. Jones ◽  
Elizabeth L. Ogden ◽  
Mark K. Ehlenfeldt ◽  
Lisa J. Rowland
Keyword(s):  
Fruits And Vegetables ◽  
Anthocyanin Biosynthesis ◽  
Mechanistic Explanation ◽  
Comparative Sequence Analysis ◽  
Wild Type ◽  
Flavonoid Pathway ◽  
Transient Expression Assay ◽  
Gene Encoding ◽  
In The Wild ◽  
Anthocyanin Production

Blueberries are one of the richest sources of antioxidants, such as anthocyanins, among fruits and vegetables. Anthocyanin mutants, like the pink-fruited cultivar ‘Pink Lemonade’, are valuable resources for investigating anthocyanin biosynthesis in blueberries. In this study, we examined expression of flavonoid pathway genes during fruit development in wild-type, blue-fruited blueberries using quantitative real-time PCR. Expression was also compared between wild-type and the pink-fruited ‘Pink Lemonade’. This revealed significantly lower expression in ‘Pink Lemonade’ than in wild-type of nearly all the structural genes examined suggesting that a transcriptional regulator of the pathway was affected. Hence, we compared expression of three known regulatory genes and found that the gene encoding the transcription factor MYB1 was expressed at a significantly lower level in ‘Pink Lemonade’ than in the wild-type. To validate the capacity of this MYB1 to regulate the transcription of anthocyanin genes in blueberries, a transient expression assay was conducted. Results indicated MYB1 overexpression enhanced anthocyanin production. Comparative sequence analysis between wild-type and mutant MYB1 variants found differences in highly conserved features suggesting a mechanistic explanation for the mutant phenotype. Collectively, the results presented here contribute to a better understanding of mechanisms regulating anthocyanin biosynthesis in Vaccinium.

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